Microelectromechanical system (MEMS) devices have been recently utilized in order to obtain devices with variable physical properties. Examples of these MEMS devices include devices with variable physical properties, such as accelerometers, digital micromirror devices (DMDs), and devices with variable electrical properties, such as variable capacitors or variable inductors. Generally, each of these MEMS devices comprises a moveable piece whose movement, when actuated by, e.g., an electrode, causes a change in the variable property of the device.
Generally, well-known semiconductor manufacturing techniques have been utilized to great effect in forming these moveable pieces within the MEMS devices. Using these techniques, parts which are intended to be moveable are initially manufactured as an immovable layer. Following the completion of the manufacturing of the moveable piece, the moveable layer is patterned, thereby freeing the moveable piece to move.
Additionally, to meet customer demands for smaller and smaller devices, the MEMS devices also need to be reduced in size so that they fit into the desired packages (e.g., mobile phones, music players, etc.). However, in this race to manufacture devices as small as possible to meet customer demands, technological improvements must improve as well. In particular, as sizes are scaled down, issues that were previously acceptable at larger sizes become more critical and can actually impact performance or yield of a production process or even the performance of the finished devices themselves.
Corresponding numerals and symbols in the different figures generally refer to corresponding parts unless otherwise indicated. The figures are drawn to clearly illustrate the relevant aspects of the embodiments and are not necessarily drawn to scale.